Health care cost of severe obesity and obesity-related comorbidities: A retrospective cohort study from Alberta, Canada

Background: Estimates of health care costs associated with severe obesity, and those attributable to specific health conditions among adults living with severe obesity are needed.Methods: Administrative data was used to identify adults who previously received a procedure, and had (investigational cohort) or did not have (control cohort) a body mass index >= 35 kg/m(2). Two-part models were used to estimate the incremental health care cost of severe obesity and related health conditions during a 1-year observation period.Results: Adjusting for potential confounders, the total health care cost ratio was higher in the investigational (n = 220,190) versus control (n = 1,955,548) cohort (1.32 [95 % CI: 1.32, 1.33]) with a predicted incremental cost of $2221 (95 % CI $2184, $22,265) per person-year; costs were less when obesity-related health conditions were controlled for (1.13 [95 % CI: 1.13, 1.14]; $1097 [95 % CI: $1084, $1110] per person-year). Among those living with severe obesity, incremental costs associated with specific health conditions ranged from $737 (95 % CI: $747, $728) lower (dyslipidemia) to $12,996 (95 % CI: $12,512, $13,634) higher (peripheral vascular disease) per person-year.Conclusions: Adults living with severe obesity had greater costs than those without, largely driven by obesity-related health conditions. For the Alberta adult population with a severe obesity prevalence of 11 %, severe obesity may account for an estimated additional $453-918 million in health care costs per year. Findings of this study provide rationale for resources and strategies to prevent and manage obesity and its complications.